There are a number of situations in which it is desirable to examine the uterus and fallopian tubes to evaluate female infertility. In one situation, for example, the patency of the fallopian tubes must be determined. This is usually accomplished by radiographic or laparoscopic examination.
To perform a radiographic evaluation, a radiopaque contrast liquid is injected into the uterus to enable examination under fluoroscopy of the contours of the uterus and the patency of the fallopian tube(s). This procedure is known as hysterosalpingography (HSG). When the contrast media is initially injected into the uterus, the HSG often incorrectly indicates blocked fallopian tubes. Such incorrect results are frequently due to insufficient injection pressure.
It is desirable to pressurize the uterus during injection of the contrast liquid, and a number of presently available devices attempt to do so. It is difficult to establish a seal between the uterus and the vagina, however, and leakage of the contrast liquid is a problem.
The reproductive tract can also be studied using a laparoscope, which is a tubular device inserted through an incision made in the abdomen cf the patient rather than being passed through the inside of the reproductive tract. The outside of the reproductive organs and the distal openings of the fallopian tubes near the ovaries can be examined through the laparoscope. Patency of the fallopian tubes is tested by injecting a colored dye into the uterus and observing spillage of the dye through the tubes into the abdominal cavity. Again, present injection devices may not properly seal the uterus and sufficiently high injection pressures may not be attainable. False patency test results may occur.
Particularly during laparoscopic examination, it is desirable to manipulate the uterus to permit observation of different areas of the uterus and surrounding organs. This is commonly accomplished by attempting to engage the cervix, which is the neck of the uterus, with a manipulator device. The device is inserted into the external opening of the cervix, referred to as the external os, and passed through the cervical canal into the uterus. The internal opening of the cervix is known as the internal os. Several conventional manipulator devices have a distal inflatable member which is inflated within the uterus to engage the internal os to prevent the device from pulling out of the uterus. A proximal stop is provided to prevent the device from being inserted further into the uterus.
The length of the cervical canal varies from patient to patient, however, and no one setting is appropriate for all patients. The present manipulator devices are commonly provided with a moveable proximal stop which must be manually adjusted in an attempt to properly seat against the external os. The process of adjusting the device to the different cervical lengths is cumbersome and may involve one or more resettings of the proximal stop to securely engage the cervix. Application of excessive force by the proximal stop may cause discomfort to the patient or undesired withdrawal of the distal member even when it is inflated.